Heretofore, various types of currency validators have been known. Typically, such validators are either of the "tray" or "slot" acceptor type. The invention herein is particularly adapted for implementation in slot acceptors in which a paper, offered as a valid note or piece of currency is transported through a testing area in which various tests are performed on the paper to determine its authenticity. Subsequently, the bill is carried among a note path to an escrow station where it is maintained until a requested transaction is completed, at which point the bill is dropped, punched, or otherwise inserted into a stacker. In such systems, numerous tests are performed on the paper to determine its authenticity. Such tests seek to confirm that the size, images, colors, patterns, inks, and the like on the paper being tendered are indicative of a valid piece of currency. An important element for testing the characteristics of the ink on the paper is a magnetic reading head, the same having found widespread use in the industry for such tests.
In the prior art, it has been known that the magnetic reading head must be maintained in close proximity to the tendered paper for purposes of test accuracy, resolution, and repeatability. In the past, the paper has been urged against the magnetic reading head by spring-biased rollers, or fixed physical structures maintained in close juxtaposition to the magnetic reading head. However, the prior art structures have typically resulted in only tangential contact with the reading head and, with a small area of contact, the tests have often been unreliable and subject to concern for errors. The prior art structure has been extremely sensitive, requiring careful adjustment, and often resulting in the generation of additional friction in the note transport system, requiring additional belt drive and the resultant generation of electronic noise.
The present trend in currency validators is vertical slot acceptors in which the paper is received within a slot, thence transported along a note path which quickly transforms from a horizontal to a vertical path. Securement of the paper in the transitional zone from horizontal to vertical is generally difficult to maintain. However, if the movement of the paper through such zone is ineffective, the system may jam, or the validation test may improperly fail.
In light of the foregoing, there is a need in the art for a magnetic sensing head system in which the area of contact between the note and the reading head is arcuate, rather than tangential, resulting in an increased area of such contact. There is a further need for guide means for urging the note against the magnetic reading head which is self-aligning. There is a further need in the art for a magnetic reading head system in which the guide means for urging the note against the magnetic reading head is self-tensioning. There is also a need for a transport system which efficiently and effectively moves the note through the transition from a horizontal path to a vertical path.